This project is designed to prove convincingly that reduction in the incidence of infection by using isolation facilities categorically leads to a significantly enhanced long-term survival in cancer patients, since initial studies were concerned primarily with the efficacy of prophylactic techniques per se. Since such efficacy has now been established, we plan to determine if this advantage can be turned to significantly enhancing the long-term survival of any patient with any cancer at any stage of this disease. To accomplish this goal, relatively large numbers of patients are required, and we propose studies involving children, adults, acute leukemia, various solid tumors, remission induction, and remission maintenance. The general project plan will be to randomize patients who are comparable in all recognized variables to receive chemotherapy in an isolation facility or in a conventional setting (control).